People will eventually be posting the items on the GTN from the packs. Additionally if you have a sub you'll be given free Cartel Coins each month to spend, enough to buy a pack.
Life day items can be bought seperatedly or in a pack, so it's unlikely there'll be too much GTN over flow as people will just buy what they want.
With the price (2400 for full pack and what ~600 per month = 4 months) and the "limited time" availability of these subscribers won't be able to save up in time for ONE full pack, never mind if they want it on more than one toon.
They are trying to get subscriber to HAVE
to pay extra, it seems they aren't even trying to pretend they aren't anymore.